My sister has an on going court case to get an injunction on her ex partner she has been to court and has all the paper work but her ex has not yet been served she has decided she does not want to go ahead with the injunction is it to late or what can she do?

You posted your question as an answer to someone else, I have moved it, so it may get some answers

You again asked the same question as an answer to another persons question I deleted that one

my sister has an on going court case to get an injunction on her ex partner

It depends on "injunction".
Did you mean restraining order? If the answer is yes she can do nothing.

my sister has an on going court case to get an injunction on her ex partner she has been to court and has all the paper work but her ex has not yet been served she has decided she does not want to go ahead with the injunction is it to late or what can she do?

Quite frankly, I'm concerned about you. You and your sister seem to show a pattern of getting involved with abusive men:
https://www.askmehelpdesk.com/family-law/restraining-order-ex-but-having-his-baby-536357.html

Was this question really about your sister or was it about you?